Centrifugal pump



Juiiy 21 1953 E. J. FREIY CENTRIFUGAL PUMP 2 Shets-Sheet 2 Filed July 29. 1950 Patented July 21, 1953 2,646,002 CENTRIFUGAL PUMP Edward J. Frey, Herrin, Ill., assignor to Borg- Warner Corporation, Chicago, 111., a corporation of Illinois Application July 29, 1950, Serial No. 176,668

This invention relates in general to pumps adaptable for employment in automatic clothes washing machines, and the invention is chiefly concerned with the problem of pumping water and other fluids containing solid matter in suspension and provides certain improvements in the rotors or impellers of centrifugal pumps to the end of accelerating flow by eliminating or minimizing conditions, the presence of which makes for obstruction, clogging or choking action of the pump and other friction forces tending to retard flow and tending to rapid and destructive wear.

Otherwise stated, the invention is embodied in an impeller having certain novel and useful characteristics whereby the output of the pump is considerably increased and whereby the wear on the vanes, back plate or shroud, and pump casing is considerably reduced.

More specifically stated, it is a general object and accomplishment of the invention to provide a pump and an impeller therefor adapted to effectively pass lint, hair, strings, buttons, safety pins or other foreign matter through the pump without clogging or causing damage to the propeller vanes or reducing the efjciency of the pump.

Another aspect of the invention is to provide a centrifugal pump having an impeller with dual sets of vanes to define separate chambers within the impeller, the dual sets of vanes defining one chamber as being of the Venturi type and working on the centrifugal principle to pump one portion of the fluid or liquid containing solid matter in suspension, and the same set of vanes defining a second set of chambers working upon the fluid from another portion of the casing, said vanes being arranged to provide in the central portion of the impeller a section open and free and having portions thereof adapted to coincide with the periphery of the central inlet aperture formed in the pump casing.

An ancillary object and accomplishment of the invention is to provide a new and improved pump and impeller therefor which is adapted to be economically manufactured and which is so designed as to permit the manufacture and assembly thereof in accordance with present day large scale mass production manufacturing methods of construction and assembly.

Additional objects, features and advantages of the invention disclosed herein will be apparent to persons skilled in the art after the construction and operation are understood from the within description.

10 Claims. (01. 103-403) One embodiment of the invention is illustrated in the accompanying drawings forming a part hereof and wherein like reference characters identify the same parts in the several views, and wherein Fig. 1 is a side elevational view of a pump embodying the features of the present invention and shown in its operative position secured to the tub of an automatic washing machine;

Fig. 2 is an end elevational view of the pump impeller embodying the features of the present invention;

Fig. 3 is a side elevational view of the pump impeller depicted in Fig. 2; 5

Fig. 4 is a sectional view through portions of the pump impeller depicted in Fig. 2 and being taken substantially on the plane of the line 4-4 in Fig. 2;

Fig. 5 is a sectional view through the pump depicted in Fig. 1 and illustrating the relative disposition of the pump impeller with respect to the pump housing;

Fig. 6 is a sectional view of the pump housing taken substantially on the plane of the line 6-6 in Fi 5;

Fig. '7 is an elevational view looking into the drain opening of the pump housing depicted in Figs. 5 and 6 and being taken substantially on the plane of the line in Fig. 6; and

Fig. 8 is an elevational view of the drain opening adjacent the impeller and being taken substantially on the plane of the line 88 in Fig. 6.

In the exemplary embodiment of the invention depicted in Figs. 1, 5 and 6, the pump housingjindicated in its entirety by the numeral 20, is formed of a casting to define a generally circular shape with flanged formations 2| adapted for securement of the pump housing to the lower portions of the washing machine tub 22 and defining a lower chamber 23 adapted to entrap relatively large pieces of foreign matter which may be conveniently removed from the chamber 23 by virtue of the removable bottom plate 24, said pump housing being provided with a generally circular shaped chamber 25 having an aperture 26 centrally disposed on the axis of said chamber to provide a through passage between the chamber 23 and the chamber 125.

Disposed in the chamber 25 for rotation therein is an impeller indicated in its entirety by the numeral 38 and comprises a driving shaft 3| extending outwardly from and journaled in the cover plate 32 with the exposed end being adapted to carry a drive pulley 33 which is operatively connected by a power transmission means ment thereto, and a plurality of vanes carried by the base plate 34 in confronting relationship so that the central portions thereof are open and exposed and are in register with the aperture 26 so that the fluid containing solid matter in suspension and other foreign matter will enter 1() through the aperture 26 to the central portions 35 of the impeller, and because of the centrifugal force caused by rotation of the impeller, the water and foreign material contained therein will follow the path defined by the arrows 36 and 31 (Figs. 2 and of whereupon this water and foreign material will be forced out of the chamber 25 and into the pump outlet 33 which may be connected to a drain hose (not shown).

Particular attention is directed to Figs. 2 and 6 which clearly illustrate the design and shape and relative disposition of the vanes 46 and 4| of the pump impeller 36. Heretofore, it has been the practice to equip impellers with vanes having curved or fiat driving or propelling surfaces usually emanating from the center or axis of the impeller and extending to the peripheral edges thereof. The invention departs from this practice-and provides an impeller constructed so as to receivefiuids containing solid matter in sus- 3O pension through relatively clear and open central regions of the impeller defined by the disposition of the vanes to provide separate chambers within the impeller, the vanes 40 and 4| defining one chamber 43 as being of the open runner type and working on the centrifugal principle to pump one portion of the fluid or liquid containing solid matter in suspension, and the same vanes 46 and 4| but difierent surfaces thereof defining a second set of chambers 44 and 45 working upon the r fluid from another portion of the casing, said vanes being arranged to provide in the central portion 35 of the impeller 30 a section open and free and having portions thereof adapted to coincide with the periphery of the central inlet 45 aperture 26 formed in the pump casing.

Thus, the vanes and 4| and the back plate together being arranged to define the chamber 43 which is entirely open at both sides and 41 adjacent the walls of the chamber 25, these pas- 5 sageways defined by the chamber 43 may be broadly termed Venturi shaped in that there is a throat portion 48 (Figs. 2 and 6) and also the open end portion 46.

Thus, the vanes divide the interior of the impeller into alternately arranged vane chambers 43, 44 and 45, the chamber 43 opening into the intake passageway or aperture 26 communicating with the pump chamber 23 The outlet or peripheral portions of the vanes are in close com- 6? so arranged as to receive only such liquid as may pass around the edges of the impeller and into the chamber 25. Otherwise stated, because of the close tolerances and the relative disposition of the vanes, any solid matter entering the aperture 26 will be received and carried away 4 through the chamber 43 while fluid filling the chamber 25 will be pumped out of the chamber and through the pump outlet 38 by virtue of the additional pumping action imparted by the vane formations defining the chambers 44 and 45.

In the instant design it can be seen that the vanes start from the peripheral edge 42 of the base plate 34 and extend inwardly until they reach a point approximately the size of the diameter of the aperture 26 whereupon the contour will be substantially circular in shape to follow the contour of the aperture 23 and will return to the peripheral edge 42 as shown. By disposing the vanes as illustrated hr the drawings, it can be seen that the central portions 35 are free and clear and that fluid containing solid matter in suspension and other foreign material could not wind upon any exposed corners or g sharp ends.

Another important aspect of the invention is the provision of an elongated rectangular shaped opening 50 forming the outlet connection between the chamber 25 and the pump outlet 33. This is clearly disclosed in Figs 6, 7 and 8, and it can be seen that any foreign matter, while being pushed through the pump, will conform to the inside of the pump body and will naturally assume a sub; stantially rectangular block shape prior to the entrance thereof to the pump outlet 38. Since the width of this block will be equivalent to the width of the pump body with the impeller in place, and since the dimension of the opening is large enough to receive the rectangular blockshaped foreign material, it will be easily received into the drain outlet 36 for passage therethrough to the drain hose (not shown) whereupon it may be carried away for disposition. Thus, it is im portant that the rectangular opening 56 should be equivalent to the width of the impeller vanes and afford ready passage to blocks or wads of foreign matter passing through the pump impeller.

The operation of the device is as follows: Upon actuation of the sequential controls usually employed in automatic washers the drain pump will begin to operate when the driving mechanism causes the impeller 34 to rotate. When the tub 22 is filled with water the chambers 23 and 25 will also be filled with such water as will run down into the pump housing. When the pump begins to operate, the water laden with foreign material will be drawn down into the chamber 23 which will naturally receive rela:

tively large objects, if any, and the water will then be drawn through the aperture 26 into the central regions 35 and the chamber 43 of the impeller, whereupon, due to centrifugal force the water bearing such foreign material will follow the path of the arrows 36 and 3! (Figs. 2 and 6) in a direction toward the peripheral edge of the impeller and, because of the relatively large rectangular shaped opening 56, the water bearing such foreign material will be forced outwardly of the pump housing through the drain opening 38. The vane formations defining the chambers 44 and 45 provide an additional pumping force to such fluid as will leak into the areas of the chamber 25 between the spaces of the impeller and the walls of the chamber 25. Thus, it can be seen that the path through the pump taken by the water containing foreign material will be relatively free and clear so as to prevent tangling or connection with sharp corners of any wads or loose solid material or any other foreign matter carried by the water. The disposition of the vanes of the impeller as shown in assembly and maintenance, lends itself to mass production manufacturing principles,- thus affording a substantial saving in the manufacturing cost'and a substantial---saving in repair and maintenance. 1 1 1 -From the foregoing disclosure it may be observed that I have provideda pump housing and impeller means therefor which efficiently fulfills the objectsthereof as hereinbefore set forth and which provides numerous advantages which may be summarized'as follows -;1. structurally simple efficient and durable; Economical to manufacture and readily adaptable to mass production manufacturing principles; and g I 3. The provision of a pump particularly adapt able for automatic washers and designed to effectively pass lint, hair, strings, buttons, safety pins, and other foreign matter through the pump and through the drain hose to a sink or stand pipe, without clogging, orcausing damage to the impeller vanes orreducing the efficiency of the pump While I have illustrated preferred embodiments of my invention, many modifications may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but wish to avail myself of all changes within the scope of theappended claims.

I claim: I

1. A fluid pump of the centrifugal type comprising a casing containing 'an'impeller formed ofa back plate having a plurality of vanes secured thereto to leave open passageway between the vanes and the side of the casing opposite said back plate, an inlet passageway in said casing leading to the center of the impeller, an outlet passageway in said casing leading from the periphery'of the impeller, said vanes being disposed to divide said impeller into alternately arranged vane chambers with the central regions of the impeller in register with said inlet passageway being free and unobstructed, one of said chambers defining a Venturi shaped passageway with a threat portion opening from and defining the narrowest portion of the free and unobstructed central regions of the impeller and with a relatively wide open end terminating at the periphery of the back plate of the impeller, and the remaining chambers defining passageways closed adjacent the free and unobstructed central regions of the impeller but providing a relatively wide open end terminating at the periphery of the back plate of the impeller, said casing having means defining an outlet adjacent'the periphery of the impeller.

2. In a fluid pump of the centrifugal type, an impeller formed of a back plate having a plurality of vanes secured thereto, said vanes being disposed to divide said impeller into alternately arranged chambers with the central regions of the impeller being free and unobstructed, one of said chambers defining a Venturi shaped passageway-with a throat portion opening from and defining the narrowest portion of the free and unobstructed central regions of the impeller and with a relatively wide open end terminating at the periphery of the back plate of the impeller, and the remaining chambers defining passage- 6 ways closedadjacent the free and unobstructed central regions of the-impeller but providinga relatively-wide openehdterminating at the periphery of the-back plate of the impeller.- I 3; In a fluid pump of the centrifugal type comprising acasing, an impeller disposed in said casing and comprising a back plate havinga plurality of vanes secured thereto-with the central regions. of the impeller being free and unobstructed,--a-first fluid passageway with a throat portionopeningfrom and defining the narrowest portionof the free and unobstructedcentral regions of the impeller and with a relatively wide open endterminating at! the periphery of the backplate of the impellenand a second fluid passageway closed adjacent the free and unobstructedcentral regions of the impeller but'providing arelatively wide openend terminating at the periphery of the back plate of the impeller. 43A fluid; pump of the centrifugaltype adapted to pump, liquid containing solid matter in suspension, comprising acasing and an impeller disposed therein, said casing having an inlet passageway leading to the centerv of the impeller, said impeller having'duaLsets of vanes arranged to define separate chambers within the impeller, the dual sets 'Ofhvanes defining one chamber as being or dual Venturi shape and workingon the centrifugal principle to pump that-portion'of thefluid containing solid matter insuspension, and the same set of. vanes defining a second set of chambers working upon the fluid from-another portionof the casing, said vanes being arranged to provide in the central portion of the impeller a section thereof open and unobstructed with portions coinciding with the periphery of the inlet passageway in.v said casing, said, casing having means defining an outlet. adjacent the periphery of the impeller.

5. In a fluid pump of the centrifugal type comprising a casing andadapted to pump liquid containing solid matter in suspension, an impeller disposed insaidcasing and comprising dual sets of vanes arranged to' define one chamber as being dual Venturi shaped and working on the centrifugal principle to pump that portion of the 'fluid containing solid. matter'in suspension, and

-the.same set of vanes defining a second set of chambers working upon the fluid from another portion of thecasing, said vanes being arranged to provide in the central portion by virtue of the duel shaped'Venturi chamber of the impeller a section thereof.- open and unobstructed adapted 'to receive that portionof the fluid containing 7 solid matter in suspension. 1 6. In a centrifugal pump impeller, a plurality of vanes disposed in confronting relationship each being provided with a curved inward portion disposed adjacent the central regions of the impeller but spaced away from the periphery of the impeller, and each vane being of uniform thickness throughout and extending from each side of said curved portion to the periphery of the impeller thereby to define alternately arranged chambers with the central regions of the impeller being free and unobstructed, one of said chambers defining a Venturi shaped passageway with a throat portion opening from the free end unobstructed central regions of the impeller and with a relatively wide open end terminating at the periphery of the impeller, and the remaining chambers defining passageways closed adjacent the free and unobstructed central regions of the impeller but providing a relatively wide open end terminating at the periphery of the impeller.

7. A fluid pump of the centrifugal type adapted to pump liquid containing solid matter in suspension, comprising a casing and an impeller disposed therein, said casing having an inlet passageway leading to the center of the impeller, said impeller having vanes arranged in confronting relationship so that central portions thereof define a free and unrestricted central section substantially coinciding with the inlet passageway, and the remaining portions thereof defining oppositely disposed Venturi type passageways whose throats open from the central section so that the fluid containing matters in suspension is caused by rotation of the impeller to pass from the central section through the throats of the Venturi passageways, the remaining portions of said vanes also define passageways closed adjacent the central section but providing relatively wide open ends which work on-the fluid in another part of the casing, said casing having means defining an outlet adjacent the periphery of the impeller.

8. A fluid pump of the centrifugal type adapted to pump liquid containing solid matter in suspension, comprising a casing and an impeller disposed therein, said casing having an inlet passageway leading to the center of the impeller, said impeller having vanes arranged-in confronting relationship so that central portions thereof define a free and unrestricted central section whose periphery substantially coincides With the periphery of the inlet passageway, and the remaining portions thereof define oppositely disposed Venturi type passageways whose throats open from the central section so that the fluid containing matter in suspension is caused by rotation of the impeller to pass from the inlet passageway and central section through the throats of the Venturi passageways to the periphery of the impeller, the remaining portions of said vanes -also define passageways adjacent the centralsec- T tion and throat but closed with respect to the central section and which have relatively wide open ends to receive only that fluid that may pass around the edges of the impeller, said casing having means defining an outlet adjacent the periphery of the impeller.

9. A fluid pump of the centrifugal type adapted to pump liquid containing solid matter in suspension, comprising a casing and an impeller disposed therein, said casing having an inlet passageway leading to the center of the impeller, said impeller having vanes arranged in confronting relationship so that central portions thereof define a free and unrestricted central section whose periphery substantially coincides with the 'periphery of the inlet passageway, and the remaining portions thereof define oppositely disposed Venturi type passageways whose throats open from the central section so that the fluid containing matter in suspension is caused by rotation of the impeller to pass from the inlet passageway and central section through the throat of the Venturi passageways to the periphery of the impeller, the remaining portions of said vanes also delne passageways adjacent the central portion and throat thereof but closed with respect to the central section and which have relatively wide open ends to receive only that fluid that may pass around the edges of the impeller, and an outlet passageway leading from the periphery of the impeller, said outlet being of substantially rectangular shape.

10. A fluid pump of the centrifugal type adapted to pump liquid containing solid matter in suspension, comprising a casing and an impeller disposed therein, said casing having an inlet passageway leading to the center of the impeller, said impeller having vanes arranged in confronting relationship so that central portions thereof define a free and unrestricted central section whose periphery substantially coincides with the periphery of the inlet passageway, and the remaining portions thereof define oppositely disposed Venturi type passageways whose throats open from the central section so that the fluid containing matter in suspension is caused by rotation of the impeller to pass from the inlet passageway and central section through the throats of the Venturi passageways to the periphery of the impeller, the remaining portions of said vanes also define passageways adjacent the central portion and throat thereof but closed with respect to the central section and which have relatively wide open ends to receive only that fluid that may pass around the edges of the impeller, and an outlet passageway leading from the periphery of the impeller and being of substantially rectangular shape and whose width is equal to the width of the impeller vanes.

EDWARD J. FREY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,718,396 Wheeler June 25, 1929 1,975,274 Hollander Oct. 2, 1934 2,276,077 Jacobsen Mar. 10, 1942 2,324,011 Miller July 13, 1943 FOREIGN PATENTS Number Country Date 267,300 Great Britain Mar. 17, 1927 

